security,fs,nfs,net: update security_inode_listsecurity() interface

Update the security_inode_listsecurity() interface to allow
use of the xattr_list_one() helper and update the hook
implementations.

Link: https://lore.kernel.org/selinux/20250424152822.2719-1-stephen.smalley.work@gmail.com
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: forward porting to bring this patch up to v7.1-rc1+]
Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index a9b8d482d28946ad6eaac57c68f23ce3b52d47db..a16342056ae5670e5f4678a338688abdbfaba983 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -10562,13 +10562,10 @@ static ssize_t nfs4_listxattr(struct dentry *dentry, char *list, size_t size)
                left -= error;
        }
 
-       error2 = security_inode_listsecurity(d_inode(dentry), list, left);
+       error2 = security_inode_listsecurity(d_inode(dentry), &list, &left);
        if (error2 < 0)
                return error2;
-       if (list) {
-               list += error2;
-               left -= error2;
-       }
+       error2 = size - error - left;
 
        error3 = nfs4_listxattr_nfs4_user(d_inode(dentry), list, left);
        if (error3 < 0)

diff --git a/fs/xattr.c b/fs/xattr.c
index 09ecbaaa16608a80b770058002c3d8a329e47e98..0bc3b47e6936c5b4979ed45d8ee058770dc0f093 100644 (file)
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -510,9 +510,12 @@ vfs_listxattr(struct dentry *dentry, char *list, size_t size)
        if (inode->i_op->listxattr) {
                error = inode->i_op->listxattr(dentry, list, size);
        } else {
-               error = security_inode_listsecurity(inode, list, size);
-               if (size && error > size)
-                       error = -ERANGE;
+               ssize_t remaining = size;
+
+               error = security_inode_listsecurity(inode, &list, &remaining);
+               if (error)
+                       return error;
+               error = size - remaining;
        }
        return error;
 }
@@ -1540,7 +1543,7 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
        if (err)
                return err;
 
-       err = security_inode_listsecurity(inode, buffer, remaining_size);
+       err = security_inode_listsecurity(inode, &buffer, &remaining_size);
        if (err < 0)
                return err;
 

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 2b8dfb35caed35d427b3aec07ed8206d4ce66584..65c9609ec20770759c08afa862e9988e89a1f0f4 100644 (file)
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -176,8 +176,8 @@ LSM_HOOK(int, -EOPNOTSUPP, inode_getsecurity, struct mnt_idmap *idmap,
         struct inode *inode, const char *name, void **buffer, bool alloc)
 LSM_HOOK(int, -EOPNOTSUPP, inode_setsecurity, struct inode *inode,
         const char *name, const void *value, size_t size, int flags)
-LSM_HOOK(int, 0, inode_listsecurity, struct inode *inode, char *buffer,
-        size_t buffer_size)
+LSM_HOOK(int, 0, inode_listsecurity, struct inode *inode, char **buffer,
+        ssize_t *remaining_size)
 LSM_HOOK(void, LSM_RET_VOID, inode_getlsmprop, struct inode *inode,
         struct lsm_prop *prop)
 LSM_HOOK(int, 0, inode_copy_up, struct dentry *src, struct cred **new)

diff --git a/include/linux/security.h b/include/linux/security.h
index 41d7367cf4036bfbca56e6277310f159b9347396..153e9043058f884feaf525a5b2d55adbc9d2a442 100644 (file)
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -459,7 +459,7 @@ int security_inode_getsecurity(struct mnt_idmap *idmap,
                               struct inode *inode, const char *name,
                               void **buffer, bool alloc);
 int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
-int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
+int security_inode_listsecurity(struct inode *inode, char **buffer, ssize_t *remaining_size);
 void security_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop);
 int security_inode_copy_up(struct dentry *src, struct cred **new);
 int security_inode_copy_up_xattr(struct dentry *src, const char *name);
@@ -1097,7 +1097,8 @@ static inline int security_inode_setsecurity(struct inode *inode, const char *na
        return -EOPNOTSUPP;
 }
 
-static inline int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
+static inline int security_inode_listsecurity(struct inode *inode,
+                                       char **buffer, ssize_t *remaining_size)
 {
        return 0;
 }

diff --git a/security/security.c b/security/security.c
index 4e999f0236516669c67dec70307873e30734a2ad..71aea8fdf014297e23c8668bdd4fcee96ff34f9b 100644 (file)
--- a/security/security.c
+++ b/security/security.c
@@ -2258,22 +2258,22 @@ int security_inode_setsecurity(struct inode *inode, const char *name,
 /**
  * security_inode_listsecurity() - List the xattr security label names
  * @inode: inode
- * @buffer: buffer
- * @buffer_size: size of buffer
+ * @buffer: pointer to buffer
+ * @remaining_size: pointer to remaining size of buffer
  *
  * Copy the extended attribute names for the security labels associated with
- * @inode into @buffer.  The maximum size of @buffer is specified by
- * @buffer_size.  @buffer may be NULL to request the size of the buffer
- * required.
+ * @inode into *(@buffer).  The remaining size of @buffer is specified by
+ * *(@remaining_size).  *(@buffer) may be NULL to request the size of the
+ * buffer required. Updates *(@buffer) and *(@remaining_size).
  *
- * Return: Returns number of bytes used/required on success.
+ * Return: Returns 0 on success, or -errno on failure.
  */
 int security_inode_listsecurity(struct inode *inode,
-                               char *buffer, size_t buffer_size)
+                               char **buffer, ssize_t *remaining_size)
 {
        if (unlikely(IS_PRIVATE(inode)))
                return 0;
-       return call_int_hook(inode_listsecurity, inode, buffer, buffer_size);
+       return call_int_hook(inode_listsecurity, inode, buffer, remaining_size);
 }
 EXPORT_SYMBOL(security_inode_listsecurity);
 

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 97801966bf32c23383a5e3775a030a03f23e5f86..4ae7367555578c06b4abe481a99b836f090a6cda 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3684,16 +3684,12 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
        return 0;
 }
 
-static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
+static int selinux_inode_listsecurity(struct inode *inode, char **buffer,
+                               ssize_t *remaining_size)
 {
-       const int len = sizeof(XATTR_NAME_SELINUX);
-
        if (!selinux_initialized())
                return 0;
-
-       if (buffer && len <= buffer_size)
-               memcpy(buffer, XATTR_NAME_SELINUX, len);
-       return len;
+       return xattr_list_one(buffer, remaining_size, XATTR_NAME_SELINUX);
 }
 
 static void selinux_inode_getlsmprop(struct inode *inode, struct lsm_prop *prop)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 3f9ae05039a28850bb2355e0bc8b5c5f8ae23873..ff115068c5c06f237f90074128ace1f0e3f60f27 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1665,17 +1665,12 @@ static int smack_inode_getsecurity(struct mnt_idmap *idmap,
  * smack_inode_listsecurity - list the Smack attributes
  * @inode: the object
  * @buffer: where they go
- * @buffer_size: size of buffer
+ * @remaining_size: size of buffer
  */
-static int smack_inode_listsecurity(struct inode *inode, char *buffer,
-                                   size_t buffer_size)
+static int smack_inode_listsecurity(struct inode *inode, char **buffer,
+                                   ssize_t *remaining_size)
 {
-       int len = sizeof(XATTR_NAME_SMACK);
-
-       if (buffer != NULL && len <= buffer_size)
-               memcpy(buffer, XATTR_NAME_SMACK, len);
-
-       return len;
+       return xattr_list_one(buffer, remaining_size, XATTR_NAME_SMACK);
 }
 
 /**